Aviation Industry Corp of China, the nation's leading aircraft maker, has declassified the twin-seat variant of its J-20 stealth fighter jet and plans to display it at an upcoming arms show.

This is the first time the State-owned defense conglomerate has officially confirmed the existence of the J-20S, the world's first and only model of a two-seater stealth combat aircraft.

According to Wu Jiwei, the company's spokesman, the J-20S is a heavy-duty radar-evading fighter jet with long-range operation and multifunction capabilities.

The new jet is characterized by its supreme ability to seize superiority in air combat, carry out precision strikes against land and sea targets, and perform battlefield situational awareness, electronic jamming and tactical command and control operations, he said on Sunday in Zhuhai, Guangdong province, the host city for the biennial China International Aviation and Aerospace Exhibition.

Wu noted that in addition to conventional tasks, the J-20S can team up with unmanned planes in air combat.

The 15th China International Aviation and Aerospace Exhibition is scheduled to take place from Tuesday to Nov 17. Popularly known as the Zhuhai Airshow, the exhibition is the largest and most important occasion for the country's defense contractors to showcase their latest technologies and hardware to the public.

The J-20S was designed by the AVIC Chengdu Aircraft Design and Research Institute in Sichuan province based on its J-20 baseline, single-seat model, which is China's first stealth combat aircraft.

As the most sophisticated and powerful fighter jet in the nation, the J-20 conducted its debut flight in January 2011 and was officially declassified in November 2016, when it staged a brief flight performance at the 11th China International Aviation and Aerospace Exhibition.

It was commissioned to the People's Liberation Army Air Force later that year, becoming the third stealth fighter jet in the world to enter service following the United States' F-22 Raptor and F-35 Lightning II.

Song Zhongping, a military affairs commentator and retired PLA officer, said a twin-seat fighter jet is normally operated by a pilot in the front seat and a weapons operator in the rear seat, which means each of them can better focus on their specific tasks.

"According to an introduction from the AVIC, the J-20S has good situational awareness capability, and that means it can act as a small-sized early-warning platform. The new model can also guide drones to carry out strikes against targets. All these new functions promise longer detection and fighting range," he said.

Fu Qianshao, an aircraft expert who served with the PLA Air Force for decades, said an extra seat in a stealth fighter has more benefits.

"The twin-seat variant can have a backup flight-control system installed for the operator in the rear seat to use in case the main system malfunctions or is damaged in action, or the pilot is incapacitated," he said.

Having a separate weapons operator can also enable the J-20S to better use precision-guided munitions and connect with the airborne early warning and control system, he added.